Japanese JLPT Grammar Point
~ことだ (〜koto da)

~ことだ (〜koto da)

Short explanation:

Expresses an advice or recommendation; 'should', 'it is important', 'it is necessary'.

Formation:

Verb-ますstem + ことだ, い-Adjective + ことだ,な-Adjective + なことだ, Noun + のことだ

Examples:

毎日運動することだ。
Mainichi undou suru koto da.
You should exercise every day.
健康のために、野菜をたくさん食べることだ。
Kenkou no tame ni, yasai wo takusan taberu koto da.
For your health, you should eat lots of vegetables.
勉強しているとき、静かな場所を選ぶことだ。
Benkyou shiteiru toki, shizuka na basho wo erabu koto da.
When studying, you should choose a quiet place.
辞書を使って、新しい言葉を覚えることだ。
Jisho wo tsukatte, atarashii kotoba wo oboeru koto da.
You should use a dictionary to learn new words.

Long explanation:

The ~ことだ grammar point is used to express a piece of advice or a recommendation to someone. It can be translated as 'should', 'it is important', or 'it is necessary' in English. The formation differs depending on whether it is used with a verb, い-adjective, な-adjective, or noun.

Detailed Grammar notes:

Processing keyword: ~ことだ (〜koto da)

Japanese Grammar Point: ~ことだ (〜koto da)

~ことだ (〜koto da)

Introduction

In this lesson, we'll explore the Japanese grammar point ~ことだ (〜koto da). This expression is frequently used to give advice or suggest that someone should (or should not) do something. Understanding how to use ~ことだ correctly will enhance your ability to express recommendations and comprehend nuances in everyday conversations.


Core Grammar Explanation

Meaning

~ことだ is used to:

  • Offer advice or suggestions.
  • Indicate that something is important to do.
  • Convey a recommendation with a mildly imperative tone. It translates roughly to "should" or "ought to" in English.

Usage

Formation:

[Verb (dictionary form)] + ことだ
[Verb (ない-form)] + ことだ
  • For positive suggestions, use the dictionary form of the verb.
  • For negative suggestions, use the ない-form (negative form) of the verb.

Structure Diagram

Suggestion Type Verb Form + ことだ
Positive Dictionary form ことだ
Negative ない-form (negative) ことだ

Comparative Analysis

Similar Grammar Points:

  1. ~ほうがいい (〜hou ga ii)
    • Meaning: "Had better" or "should."
    • Usage: Can be used with past tense verbs for stronger advice or admonishment.
    • Example: 早く寝たほうがいい。
      Hayaku neta hō ga ii.
      You had better sleep early.
  2. ~べきだ (〜beki da)
    • Meaning: "Should" or "ought to," expressing a moral obligation.
    • Usage: Stronger than ~ことだ, emphasizes a sense of duty.
    • Example: 約束は守るべきだ。
      Yakusoku wa mamoru beki da.
      You should keep your promises. Nuances:
  • ~ことだ is softer and more conversational than ~べきだ.
  • ~ほうがいい can carry a sense of urgency or stronger suggestion.

Examples in Context

Formal Situations

  1. 健康のために野菜を食べることです**。
    Kenko no tame ni yasai wo taberu koto desu.
    You should eat vegetables for your health.
  2. 会議には時間通りに出席することです**。
    Kaigi ni wa jikan doori ni shusseki suru koto desu.
    You should attend the meeting on time.

Informal Situations

  1. 疲れたら早めに寝ることだ**。
    Tsukaretara hayame ni neru koto da.
    If you're tired, you should go to bed early.
  2. 無理をしないことだ**よ。
    Muri wo shinai koto da yo.
    You shouldn't overdo it.

Various Contexts

  1. 日本語が上手になりたいなら、毎日勉強することだ**。
    Nihongo ga jouzu ni naritai nara, mainichi benkyou suru koto da.
    If you want to improve your Japanese, you should study every day.
  2. 遅刻しないように、早く家を出ることだ**。
    Chikoku shinai you ni, hayaku ie wo deru koto da.
    To avoid being late, you should leave home early.

Cultural Notes

Cultural Relevance

  • Politeness Levels: Using ~ことだ is appropriate in both formal and informal settings but can be made more polite by using です (desu): ~ことです.
  • Social Norms: Giving advice using ~ことだ is generally acceptable, but always consider the social hierarchy and relationship between speakers to maintain politeness.

Idiomatic Expressions

  • 焦らないことだ**。
    Aseranai koto da.
    You should not rush.
  • 諦めないことだ**。
    Akiramenai koto da.
    You shouldn't give up.

Common Mistakes and Tips

Error Analysis

  1. Incorrect Verb Form:
    • Incorrect: 遅刻したことだ。
      Chikoku shita koto da.
      (Using past tense form)
    • Correct: 遅刻しないことだ。
      Chikoku shinai koto da.
      You should not be late. Tip: Always use the dictionary form or the ない-form before ことだ.
  2. **Confusion with Explanatory ことだ
    • Note: ~ことだ in this context is different from when こと is used to nominalize verbs or explain situations.

Learning Strategies

  • Mnemonic Device: Think of ことだ as "It's a matter of..." leading to advice.
  • Practice Exercises: Create sentences giving advice to yourself to internalize the pattern.

Summary and Review

Key Takeaways

  • ~ことだ is used to offer advice or mild suggestions.
  • Formed by attaching ことだ to the dictionary form or ない-form of a verb.
  • Softer in tone compared to ~べきだ and can be more polite with です.

Quick Recap Quiz

  1. How do you form a suggestion using ~ことだ?
    • Answer: Attach ことだ to the dictionary form (for positive advice) or the ない-form (for negative advice) of a verb.
  2. Translate into Japanese: "You should listen carefully."
    • Answer: よく聞くことだ。
      Yoku kiku koto da.
  3. What is the difference between ~ことだ and ~べきだ?
    • Answer: ~ことだ offers mild advice or suggestions, while ~べきだ expresses a stronger sense of moral obligation or duty.

By mastering ~ことだ (〜koto da), you'll be able to give and understand advice effectively, enriching your Japanese communication skills!

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Public Alpha version Open Source (GitHub). This site is currently undergoing active development. You may (will) encounter bugs, inconsistencies, or limited functionality. Lots of sentences might not sound natural. We are progressively addressing these issues with native speakers.


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